The present invention relates to a fan-coil three way control equipped with an automatic air vent for air conditioning automatically removing all pockets of air as they can be accumulated in the cooling coil of the fan-coil unit and to keep heat exchange efficiency.
Most business and commercial buildings nowadays have a closed interior space. Air conditioning becomes very important to those buildings.
FIG. 1 illustrates a conventional fan-coil unit A that is generally being installed under the slab of the building. It has a chilled water supply branch pipe A1 and a chilled water return pipe A2 connecting from main chilled water supply pipe A3 and main chilled water return pipe A4 that located beneath the beam. And there is a manual air vent valve B in the fan-coil unit A to vent the air.
As the space around the fan-coil unit A is relatively small, venting the manual air vent valve B may be not so difficult during the period of installation because of no much obstacles have been built yet, but it is not so easy or convenient once installation and interior decoration are completed. To venting the manual air vent valve become a tedious job after installation. Maintenance people usually have to crawl into the manholes to unfasten the manual air vent valve B to vent residual air trapped in the cooling coil of the fan-coil unit A. Otherwise air will be accumulated in the cooling coil and result in decreasing of heat exchange efficiency of the fan-coil unit and reducing air conditioning effect.
A large building usually has many fan-coil units to meet air conditioning requirements in the big closed environment. It takes a great amount of maintenance labors and time to vent exhaust air from the fan-coil units. It is a big cost item.
Moreover, fan-coil control valves now available on the market are generally grouped as diverting type and mixing type. The diverting type design includes a complicated piping arrangement. Hence, the mixing type design may be preferable.
In view of the foregoing disadvantages, the primary object of the invention is to provide an improved fan-coil control valve that has an automatic air vent valve coupled with a mixing type three-way or two-way control valve to vent air more conveniently for fan-coil units.
The invention mainly includes an automatic air vent valve installed on a three-way control valve located between a chilled water supply branch pipe and a chilled water return branch pipe to generate automatic air vent effect, thereby to remove all pockets of residual air as they can be accumulated in the cooling coil of the fan-coil unit to maintain high efficiency of heat exchange.
The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.